Method for carrying out an automatic can changing process at a spinning station of a spinning machine, and spinning machine and movable can changer

ABSTRACT

A method carries out an automatic can change process at a spinning station of a spinning machine where a sliver is delivered to a spinning device from a sliver can positioned underneath the spinning station using a movable can changer that includes a can gripper. A length of a sliver residue is predefined and stored. Once the predefined length of the sliver residue length has been reached, the sliver is separated while production of a yarn from the sliver is underway at the spinning station. The sliver is clamped at the sliver can with a fixed clamp on the can changer, wherein separation of the sliver is performed by, with the can changer, removing the sliver can with the clamped sliver from the spinning station, or additionally clamping the sliver with a movable clamp on the can changer and moving the movable clamp relative to the fixed clamp.

FIELD OF THE INVENTION

The present invention relates to a method for carrying out an automatic can changing process at a spinning station of a spinning machine by means of a movable can changer that includes a can gripper, in which a sliver is delivered to the spinning station from a sliver can positioned underneath the spinning station, wherein a sliver residue length of the sliver is predefined and, once the predefined sliver residue length has been reached, the sliver is separated while production is underway at the spinning station.

BACKGROUND

A can change is necessary with spinning machines, for example, within the scope of a lot change or when a sliver can is empty. It is not always possible to use up or spin all the sliver from the old sliver can to be exchanged before the can change is carried out. The sliver or the sliver can is usually exchanged before the sliver can is empty, since this makes it possible to reduce the unproductive downtimes at the spinning stations as compared to carrying out an exchange only once the sliver cans are empty. In order to carry out a can change, therefore, the sliver delivered to the spinning station from the sliver can must first be separated. In addition, the new sliver must be fed to the spinning station after the sliver can or the fiber material has been exchanged.

It is known from DE 25 21 851 A1 to carry out the can change at all spinning stations of a spinning machine simultaneously or only shortly one after the other. For this purpose, the sliver cans are filled with slivers of the same length and the can changing process is initiated once a predetermined length of the sliver has been reached. The intake devices of the spinning stations in DE 25 21 851 A1 are centrally driven by means of a common drive. In order to carry out the can change, initially the sliver is separated at each spinning station using a smooth cut directly ahead of the intake device by means of a spinning station-specific separating device. The sliver residue is spun, wherein, due to the smoothly cut sliver end, the yarn is intended to form a thick place at its end.

A problem addressed by the present invention is that of providing a method, which improves an automatic can changing process at a spinning machine. An appropriate spinning machine and an appropriate can changer are also to be provided.

SUMMARY OF THE INVENTION

The problem is solved using a method, a spinning machine and a can changer having the features of the independent patent claims. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In a method for carrying out an automatic can changing process at a spinning station of a spinning machine by means of a movable can changer that includes a can gripper, a sliver is delivered to the spinning station from a sliver can positioned underneath the spinning station. A sliver residue length of the sliver is predefined and, once the predefined sliver residue length has been reached, the sliver is separated while production is underway at the spinning station.

It is provided that the sliver is clamped at the sliver can by a fixed clamp of the can changer, more particularly of the can gripper, and that the sliver can is removed from the spinning station by the can changer together with the clamped sliver and, as a result, the sliver is separated. The can changing process can be carried out particularly quickly as a result, since the separation of the sliver takes place directly with the exchange or the removal of the sliver can to be exchanged. A synchronization with elements of the spinning stations for this purpose is not necessary. The unproductive downtimes of the spinning stations can therefore be further reduced. It is also advantageous that separating devices are no longer necessary at the individual spinning stations. As a result, the spinning machine can be designed to be simpler. Due to the clamping of the sliver at the sliver can, a defined, reproducible separation point can nevertheless be produced in the sliver, which facilitates the further handling of the sliver during further spinning or even during disposal.

According to one alternative embodiment, it is provided that the sliver is clamped at the sliver can by a fixed clamp of the can changer, more particularly of the can gripper, and the sliver is additionally clamped by a movable clamp and separated by moving the movable clamp. As a result, in addition, the can changing process can be carried out quickly and the unproductive downtimes of the spinning stations can be reduced. Separating devices at the spinning stations are not necessary here, either. Due to the movable clamp, it is possible to avoid uncontrolled breakage of the sliver with formation of thin places in the delivered sliver, which can result in yarn defects as spinning continues. Due to the two-fold clamping by means of the fixed clamp and the movable clamp, a separation of the sliver at a reproducible point between the two clamps is achieved, at which the sliver is not impermissibly thinned out.

In an appropriate spinning machine that includes a plurality of adjacently arranged spinning stations, wherein each of the spinning stations has a supply device for supplying a sliver, which is to be spun, to the spinning station, and a measuring device, by means of which a sliver residue length of the sliver to be spun is ascertainable, and that includes at least one control unit in which a sliver residue length of the sliver is predefinable, at which sliver residue length an automatic can changing process is to be initiated, it is provided that the spinning station and/or the spinning machine have/has a control unit for carrying out the described method.

The spinning machine can be designed, for example, as a rotor spinning machine, wherein the supply device for supplying the sliver includes a feeder. The method can also be used on an air-jet spinning machine, however. The supply device for supplying the sliver is a drafting system in this case. The measuring device is in control connection with the control unit in order to initiate the automatic can changing process.

With respect to a movable can changer that includes a can gripper for carrying out an automatic can changing process, it is therefore provided that the can changer, more particularly the can gripper, includes a fixed clamp for clamping a sliver at the sliver can. As described, the can changer can therefore carry out the can changing process entirely automatically without a need to synchronize with elements of the spinning station.

It is advantageous when the can changer additionally includes a movable clamp for separating the sliver. As a result, the can changer can enable a separation of the sliver in a reproducible manner without the formation of thin places.

With respect to the method, it is advantageous when the sliver can is initially pulled by the can changer out of its position underneath the spinning station into a position in front of the spinning station before the sliver is clamped and the sliver is clamped at a front edge of the sliver can facing the spinning station. The clamping point at which the fixed clamp clamps the sliver at the sliver can is therefore situated particularly close to the spinning station, thereby facilitating the formation of a defined and reproducible separation point.

According to a first enhanced embodiment of the method, it is also advantageous when, once the sliver has been separated, sliver residue remaining at the spinning station is spun. Due to the fact that the fixed clamp of the can gripper ensures that a defined separation point is produced and the sliver does not break in an uncontrolled manner, the sliver residue can be spun without greater yarn defects arising, more particularly in simpler applications. The yarn that is produced therefore has a largely consistent quality up to the end of the sliver residue.

According to another enhanced embodiment, once the sliver has been separated, a piece of sliver residue remaining at the spinning station is disposed of, more particularly removed by suction. This is advantageous more particularly in the manufacture of yarn lots having high quality requirements, since the separation point does not enter into the finished yarn. The discarded or sucked-off sliver residue, possibly together with other sliver residue, can be separately recycled or made available for another application.

With respect to the disposal of the sliver residue, it is advantageous when the sliver residue is removed via suction by means of a suction device of the spinning machine, more particularly a spinning station-specific suction device. With respect to the spinning machine, it is therefore advantageous when the spinning machine includes a suction device, by means of which sliver residue remaining at the spinning station after the separation of the sliver can be removed by suction.

For this purpose, a spinning station-specific suction device is preferably arranged at each of the spinning stations. The suction device is preferably connected to a negative pressure channel of the spinning machine, which is present anyway. Alternatively to a spinning station-specific suction device at each of the spinning stations, a suction device is also conceivable that, although being machine-mounted, is assigned to multiple spinning stations. For example, a suction arm could be arranged at each section side, which removes by suction the slivers at all spinning stations of this section side.

According to another enhanced embodiment of the invention, the suction device of the spinning machine is arranged in a movable service device. This is advantageous more particularly for the case in which a movable service device is necessary anyway at the spinning machine, for example, in order to piece the new sliver at the spinning station or to carry out a bobbin change.

According to another embodiment, it is advantageous with respect to the disposal of the sliver residue when the sliver residue is removed via suction by means of a suction device of the movable can changer. With respect to the can changer, it is therefore advantageous when the can changer has a suction device for removing, via suction, sliver residue remaining at the spinning station after the sliver has been separated. As a result, the sliver residue can be advantageously collected separately from other fiber waste from the spinning machine and fed to a separate recycling process. It is particularly advantageous in this case as well that the can changer can carry out the can changing process automatically without synchronizing with further elements of the workstation.

With respect to the method, it is also advantageous when, once the sliver has been separated, the spinning device is stopped, and the sliver residue is fed to the stopped spinning device and sucked off of the spinning device. A separate suction device is not necessary for disposing of the sliver. The sliver residue is fed to the stopped spinning device by means of the supply device, which is present anyway, and is sucked off via a suction point of the spinning device, which is present anyway. Preferably, the sliver is opened into individual fibers for this purpose prior to removal via suction.

In any case, it is advantageous that the sliver does not need to be unthreaded from a sliver guide of the spinning station prior to removal by suction or spinning, which also simplifies the can changing process.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the invention are described in the following exemplary embodiments, wherein:

FIG. 1 shows an overview representation of a spinning machine in a schematic front view,

FIG. 2 shows a schematic side view of spinning station of a spinning machine with a can changer that includes a fixed clamp prior to an automatic can changing process,

FIG. 3 shows the spinning station from FIG. 2 after the clamping of the sliver,

FIG. 4 shows the spinning station from FIG. 2 after the separation of the sliver,

FIG. 5 shows the spinning station from FIG. 2 during the removal by suction of the sliver according to a first embodiment,

FIG. 6 shows the spinning station from FIG. 2 during the removal by suction of the sliver according to a second embodiment,

FIG. 7 shows a section of a spinning machine with a movable service device that includes a suction unit for removing by suction the sliver in a schematic front view,

FIGS. 8 & 9 show a truncated representation of a spinning station during the removal by suction of the sliver according to a third embodiment in a schematic front view,

FIG. 10 shows a schematic side view of spinning station of a spinning machine with a can changer that includes a fixed clamp and a movable clamp prior to an automatic can changing process, and

FIG. 11 shows the spinning station from FIG. 10 after the separation of the sliver.

DETAILED DESCRIPTION

In the following description of the alternative exemplary embodiments represented in the figures, the same reference signs are utilized for features that are identical or at least comparable in terms of their configuration and/or mode of operation. Provided the features are not described in detail again, their design and/or mode of operation correspond/corresponds to the design and mode of operation of the above-described features. For the sake of greater clarity, reference signs for previously described components have not been individually included in the figures.

In the following description of the exemplary embodiments, features that are identical or at least comparable with respect to their design and/or mode of operation are provided with identical reference characters. Moreover, these features are explained in detail only at their first mention, while only the differences from the previously described exemplary embodiments are discussed in the subsequent exemplary embodiments. Moreover, for the sake of clarity, often only one or only a few of several identical components and/or features is/are labeled.

FIG. 1 shows a schematic front view of a spinning machine 1 that includes a plurality of adjacently arranged spinning stations 2. The spinning stations 2 are arranged, in the usual way, between two frames 11 on one or also on both longitudinal side(s) of the spinning machine 1. Each of the spinning stations 2 includes, in the usual way, a supply device 5, by means of which a sliver 4 is delivered out of a sliver can 3 to a spinning device 6. The sliver cans 3 are placed underneath the spinning stations 2 in one row or also in multiple rows. By means of the spinning device 6, a yarn 8 is spun out of the sliver 4, the yarn 8 also being wound, as is known, onto a bobbin 7 by means of a winding device. The sliver 4, after exiting the sliver can 3 and before reaching the supply device 5, is guided through a sliver guide 9 at the spinning station 2, the sliver guide 9 being arranged underneath the supply device 5 in the present example. In the spinning machine 1 shown, a measuring device 17 is also arranged at each spinning station 2, by means of which a remaining length of the sliver 4 still located in the particular sliver can 3 can be ascertained. This can be carried out, for example, indirectly, by measuring the running length of the sliver 4 that has already been processed.

In the present example, the spinning machine 1 also has a movable service device 12 that includes service elements 24, which can carry out service operations, such as, for example, bobbin changes, cleaning processes, or also piecing processes, depending on the design of the spinning machine 1. The spinning stations 2 of the spinning machine 1 are preferably designed, however, as at least semi-autonomous spinning stations 2, which can automatically carry out at least one piecing process. The spinning stations 2 can also be fully autonomous, and therefore a movable service device 12 is not absolutely necessary.

The spinning machine 1 shown in the present case also includes a negative pressure channel 22, which extends along the spinning stations 2 and which is acted upon by vacuum from a central vacuum source 23. The negative pressure channel 22 can provide the negative pressure for spinning in the case of a rotor spinning machine. Various suction points and suction devices 19 (see FIGS. 5 through 8 ) of the spinning machine 1 can also be acted upon by means of the negative pressure channel 22.

The spinning machine also includes at least one control unit 16 for controlling the spinning stations 2 and, possibly, the movable service device 12. In the present case, a control unit 16, as a central machine control system of the spinning machine 1, is apparent. Control units 16 can additionally also be provided at the spinning stations 2, however, as shown in the present case, in order to control the working elements of the spinning stations, for example, the measuring device 17, the supply device 5, the spinning device 6, and others. Each spinning station 2 can include a separate control unit 16 as a spinning station control system, or one control unit 16 can be provided as a spinning station control system for a group of spinning stations 2.

The spinning machine 1 can be designed as a rotor spinning machine, and therefore a feeder is provided as a supply device 5. The spinning machine 1 could also be designed as an air-jet spinning machine, however, wherein the supply device 5 would then be designed as a drafting system.

With reference to FIGS. 2 through 4 , a method is presented for carrying out an automatic can changing process at a spinning station 2 of a spinning machine 1 by means of a movable can changer 14 that includes a fixed clamp 18.

FIG. 2 shows the spinning station 2 in a schematic side view. The sliver 4 is guided out of the sliver can 3 a, which is to be removed in the can changing process, through the sliver guide 9 and over the measuring device 17 before reaching the supply device 5, and is fed by the supply device 5 to the spinning device 6. The can changing process can, for example, be initiated as soon as the measuring device 17 registers that a predefined sliver residue length has been reached. The desired sliver residue length can be stored, for example, in the control unit 16 of the spinning machine 1 and/or of the spinning station 2. The measuring device 17 is in a control connection with the control unit 16 for this purpose.

The can changer 14 is summoned for the automatic can changing process, the can changer 14 carrying a full sliver can 3 b (represented using dash-dotted lines). The can changer 14 includes a can gripper 15 in order to handle the sliver cans 3 and exchange the sliver can 3 a (represented using solid lines), which is to be removed and replaced, for the full sliver can 3 b. In the view shown in FIG. 2 , the can changer 14 has already positioned itself in front of the relevant spinning station 2 and, using its can gripper 15, grasped the sliver can 3 a to be removed. The can changer 14, specifically the can gripper 15 in the present case, includes a fixed clamp 18 for clamping the sliver 4 at the sliver can 3. The fixed clamp 18 is shown in the open state in the present case. Production is still underway at the spinning station 2 at this point in time.

FIG. 3 shows the spinning station 2 from FIG. 2 after the clamping of the sliver 4. By means of the can gripper 15, the sliver can 3 a to be removed has been grasped and initially moved out of its position underneath the spinning station 2, which is shown in FIG. 2 , into a position in front of the spinning station 2. In this position, the front edge 20 of the sliver can 3, which faces the spinning station 2, is now also easily accessible, since the spinning can 3 is no longer located underneath the spinning station 2. As the sliver can 3 a to be removed is pulled forward, the sliver 4 is simultaneously laid over the edge or the front edge 20 of the sliver can. The sliver 4 is now accessible by the fixed clamp 18. By actuating the fixed clamp 18, the sliver 4 is now clamped at the front edge 20 of the sliver can 3 a. Thereafter, the sliver can 3 a, including the clamped sliver 4, can be completely transferred onto the can changer 14.

FIG. 4 shows the spinning station 2 from FIG. 2 after the separation of the sliver. The sliver can 3 a, including the sliver 4 clamped at the front edge 20 of the sliver can 3 a, has been removed from the spinning station 2 and transferred out of the pulled-forward position completely onto the can changer 14 by means of the can gripper 15. The sliver 4 was separated at the same time due to the movement of the can gripper 15. The sliver residue 21 remaining at the spinning station 2 is now exposed and can be disposed of. The disposal of the sliver residue 21 can be carried out, for example, by spinning or also by removal via suction by means of a suction device 19 (see FIG. 5 ).

FIG. 5 shows the spinning station from FIG. 2 during the removal by suction of the sliver residue 21 according to a first embodiment. According to the present representation, the spinning station 2 is provided with a spinning station-specific suction device 19. The suction device 19 has a suction opening, which, in the present case, is arranged in the area of the sliver 4 between the measuring device 17 and the supply device 5. The suction device 19 is acted upon via the negative pressure channel 22. After the separation of the sliver 4, the sliver residue 21 remaining at the spinning station 2 can be removed via suction by means of the suction device 19 and, as a result, is preferably simultaneously unthreaded from the sliver guide 9.

FIG. 6 shows another embodiment of a suction device 19, which is not arranged at the spinning station 2, but rather at the movable can changer 14. The suction device 19 in the present case includes a suction arm, which can be, for example, telescopic, and can be moved toward the sliver 4. In this embodiment as well, the sliver residue 21 is preferably unthreaded from the sliver guide 9 directly by means of the suction process itself. The sucked-off sliver residue 21 can be advantageously collected directly on the can changer 14 and fed to a separate recycling or disposal process.

FIG. 7 shows another embodiment of a suction device 19. A cutout portion of a spinning machine 1 that includes a movable service device 12 is shown in a schematic front view. The suction device 19 is provided in the present case as a service element 24 in the movable service device 12. The suction device 19 also includes a suction arm in this case, the suction arm being movable toward the sliver residue 21. For this purpose, the suction arm is transferrable from a neutral position, which is shown using dash-dotted lines, into a suction position, which is shown using solid lines.

According to FIGS. 5 through 7 , the sliver residue 21 is unthreaded from the sliver guide 9 directly via suction by means of the suction device 19. Basically, it is also conceivable, however, to unthread the sliver residue 21 from the sliver guide 9 by means of a separate handling device (not shown), which can be arranged at the spinning station 2 and also at the can changer 14.

One further embodiment of the method for disposing of the sliver residue residue 21 is shown with reference to FIGS. 8 and 9 . FIG. 8 shows the workstation 2 in a truncated representation in a front view, immediately after the sliver 4 was separated. The spinning device 6 is now stopped, although the operation of the supply device 5 continues. The sliver residue 21 remaining at the spinning station 2 is therefore fed to the stopped spinning device 6 by means of the supply device 5. The spinning device 6 includes, in a manner known per se, a suction point 13, which is at least temporarily connected to the negative pressure channel 22 for service purposes, also during an on-going spinning operation in the case of a rotor spinning device. The sliver residue 21 or its individual fibers (not shown) can therefore be removed via the suction point 13, which is present anyway, and the negative pressure channel 22, which is present anyway. The suction point 13 therefore also forms a suction device 19 of the workstation 2. FIG. 9 shows the workstation 2 immediately after the sliver residue 21 has been removed by suction.

The workstation 2 shown in the present case is designed as a workstation of a rotor spinning machine. An opening device 25, in which the sliver 4 is opened into individual fibers, is therefore also positioned downstream from the supply device 5, which is designed as a feeder in this case. The sliver residue 21 is therefore also removed by suction in the form of individual fibers. This is not absolutely necessary, however. In the case of an air-jet spinning machine as well, the spinning device 6 is generally provided with a suction point 13, via which the sliver residue 21 could be removed by suction.

FIGS. 10 and 11 also show a spinning station 2 of a spinning machine 1 that includes a can changer 14 having a fixed clamp 18 and a movable clamp 10 in a schematic side view.

FIG. 10 shows the spinning station 2 and the sliver 4 before the separation. In contrast to the embodiment from FIG. 3 , once the sliver can 3 a to be removed has been pulled out of its position underneath the spinning station 2 into the position in front of the spinning station 2, the sliver 4 has now been additionally clamped by means of a clamp 10, which is movably arranged at the can gripper 15.

The sliver 4 is now separated not by moving or removing the sliver can 3 a, which is to be removed, but rather by moving the movable clamp 10. This is shown in FIG. 11 . The movable clamp 10, with the sliver 4 clamped therein, is moved away from the fixed clamp 18 to a certain extent, as a result of which the sliver 4 was separated. As a result, a very clean, defined separation point can be produced in the sliver 4 in a particularly advantageous way, the separation point also not causing any significant yarn defects when the sliver residue 21 is spun. As a result, a yarn having consistent quality can be provided up to the point at which the separation point is reached, as a result of which the spinning process is terminated.

The present invention is not limited to the represented and described exemplary embodiments. Modifications within the scope of the claims are also possible, as is any combination of the described features, even if they are represented and described in different parts of the description or the claims or in different exemplary embodiments, provided no contradiction to the teaching of the independent claims results.

LIST OF REFERENCE CHARACTERS

-   -   1 spinning machine     -   2 spinning station     -   3 sliver can         -   3 a sliver can to be removed         -   3 b full sliver can     -   4 sliver     -   5 supply device     -   6 spinning device     -   7 bobbin     -   8 yarn     -   9 sliver guide     -   10 movable clamp     -   11 frame     -   12 movable service device     -   13 suction point     -   14 can changer     -   15 can gripper     -   16 control unit     -   17 measuring device     -   18 fixed clamp     -   19 suction device     -   20 front edge     -   21 sliver residue     -   22 negative pressure channel     -   23 vacuum source     -   24 service element     -   25 opening roller 

1-11: (canceled)
 12. A method for carrying out an automatic can changing process at a spinning station of a spinning machine where a sliver is delivered to a spinning device at the spinning station from a sliver can positioned underneath the spinning station, the method using a movable can changer that includes a can gripper, the method comprising: predefining and storing a value for a length of a sliver residue; once the predefined value for the length of the sliver residue length has been reached, separating the sliver while production of a yarn from the sliver is underway at the spinning station; clamping the sliver at the sliver can with a fixed clamp on the can changer; wherein separation of the sliver is performed by one of: with the can changer, removing the sliver can with the clamped sliver from the spinning station; or additionally clamping the sliver with a movable clamp on the can changer and moving the movable clamp relative to the fixed clamp.
 13. The method according to claim 12, comprising initially pulling the sliver can out from under the spinning station into a position in front of the spinning station before clamping the sliver before clamping the sliver at a front edge of the sliver can facing the spinning station.
 14. The method according to claim 12, comprising continuing to spin the sliver residue left at the spinning station after separation of the sliver.
 15. The method according to claim 12, comprising removing the sliver residue left at the spinning station after separation of the sliver.
 16. The method according to claim 15, wherein the sliver residue is removed by a suction device of the spinning machine.
 17. The method according to claim 12, wherein once the sliver has been separated, the spinning device is stopped, and the sliver residue is fed to the stopped spinning device and sucked off of the spinning device.
 18. A spinning machine, comprising: a plurality of adjacently arranged spinning stations, each of the spinning stations comprising a spinning device; each of the spinning stations comprising a supply device configured to supply a sliver to the spinning device; each of the spinning stations comprising a measuring device configured to determine a length of sliver residue to be spun; a control unit, a value for the length of sliver residue predefined and stored in the control unit; and wherein the control unit is configured to carry out the method according to claim 12 to initiate the automatic can changing process at the spinning station when the value for the length of the sliver residue is reached at the spinning station.
 19. The spinning machine according to claim 18, further comprising a suction device configured to remove the sliver residue remaining at the spinning station after the sliver has been separated.
 20. A movable can changer, comprising: a can gripper; a fixed clamp configured on the can gripper; and wherein the movable can changer is configured to perform the method according to claim 12 for carrying out the automatic can changing process at the spinning station of the spinning machine.
 21. The movable can changer according to claim 20, further comprising a movable clamp configured on the can gripper.
 22. The movable can changer according to claim 20, further comprising a suction device configured to remove the sliver residue remaining at the spinning station after the sliver has been separated. 